they're normal, happy kids in cambridge, and then something happens, a switch is flipped. how can the fbi, how can homeland security notice when that happens? when the radicalization occurs, especially when it's self-radicalization online. it's very, very difficult to do. what i want to know, what did the russians do when he went back to russia? they had already said that they were interested in him, he went back and spent six months. what did they do? did they follow him around? >> we're dealing with something of a new pattern since 9/11. attempts at terrorist attacks by people who have been in the united states for quite a long period of time who have become radicalized. not the times square bomber, had some connections overseas. but not parts of larger broader conspiracies. >> this will probably turn out that way, self-radicalization. the issue here is, now that people have seen what two people did with easily obtained materials, closed down a city, other people around the country who have been radicalized have watched this and they're going to wonder, is there a way no